Albeet e



Patented u A. E. ELMER.

HOLLOW SPINDLE CHUCK.

(N Model.)

UNITED STATE-s ALBERT ELMER, SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO GARVIN St OO., OF NEW YORK, N. Y.

PATENT OFFICE.

HOLLOW SPINDLE-CHUCK.

SPECIFICATION forming part of Letters Patent No. 347,167, dated August l 1886.

Application filed October 15, 1885. Renewed July 15, 1886. Serial No. 208,075. (No model.)

To all whom/t may concern.'

Be it known that I, ALBERT E. ELMER, a

citizen ofthe United States, residing in Springfield, county of Hampden, and State of Massachusetts, have invented certain new and useful Improvements in Hollow Spindle-Chucks, fully described and represented in the following specification and the accompanying drawings, forming a part of the same. v

This invention relates, chiefly,to an improvement in the heads of screw-machines, through the spindle of which rods are fed from the rear end and clamped by a chuck at the nose of the spindle. Such chucks are usuallyformed by fitting a hollow conical plug to a corresponding seat, the plug being split so as to clamp the rod when forcedinto its conical seat, which forceis exerted by the movement of a hollow tudinally, which means may be applied to the spindle at its rear end, or at any other` point,

the drawings showing two constructions adapted for location at different points upon the spindle. It also consists ina hardened bushing for the chuck-plug seat.

The nature of these improvements will be understood by reference to the annexed drawings, in which- Figure l is a rear view of the bearing for the hollow spindle, with the collar G and the levers I and their head H omitted, to `expose the cone and its shifting device.- Fig. 2 is a side elevation of the spindle-head in section on line :v w in Fig. 3. Fig. 3 is a plan of the same, an'd Fig. 4 is an end view of the head '6, 7, and 8 are on a larger scale than the other 5g views. c'

Referring to Figs. l to 4, inclusive, Ais'the body of the casting, upon which the spindlebearings B B are formed. l

Gis the spindle, and D acone attached thereto.

vE is the conical chuck-plug; F, the sleeve, movable within the spindle, to press such plug to its tapering seat.

Gis a collar secured to the sleeve.

H is a head secured upon the spindle adjacent to the collar, and I are levers pivoted in notches in the head H. Both ends of each lever extend longitudinally along the spindle, one end of the lever bearing against the face of the collar G and the other end being-actuated by a cone, J, whose sloping sides force such end out from the spindle and press inward the ends in contact with the collar G. rIhe face G of the collar is inclined, beveled, or otherwise shaped in reference to the leverfulcrum I, so that the lateral movement of the lever thrusts the collar longitudinally, and moves the sleeve F, to press the conical plug E to its seat. The collar G is moved back to its normal position by the elastic pressure of the chuck-jaws against their tapering seats.

The sleeve F is extended beyond the rear end of the spindle, and the collar G is attached directly thereto by the screws Z, and in this construction the spindle C itself is projected beyond the rear bearing, B, to apply the head H and cone J to the spindle adjacent to the collar. The cone J is grooved at J 2,to receive a shifter, the latter being shown only.in connection with the construction shown in Figs. l, 2, and 3, where the collar G is tted directly upon the end of the sleeve which projects at the rear of the spindle G. The shifter m is constructed with a hub, m', fitted to slide upon a stud, n, which is projected from the rear side of the bearing B, and a lever, O, is pivoted to a fulcrum, P, adjacent to the stud, and passed through a slot, q, inthe hub of the shifter. The handle of the lever O thus operates when moved to and fro to shift the cone J and to open or close the conical chuck-plug. It will be noticed that in this invention both arms of the lever I lie outside of the spindle and extend longitudinally along the same between the collar G and the cone J, and to effect a roo contact of the collar with the ends of such levers the collar is required to project beyond the periphery of the spindle.

Having thus described a construction with the cone J at the projecting end of the spindle, I will refer to Fig. 5, in which it is applied between the journals b b, at which points the spindle C is fitted to the bearings B B, and in which figure the chuck is shown of different form. In this figure the plug E is fitted insidea shell, K, which is screwed upon the nose of the spindle, as at L', and is contracted outwardly, so that the plug requires an outward movement to clamp it upon the rod S, the plug being split, as in the other construction shown in Fig. 7. The collar lettered Gl in Figs. 5 and 6, being applied to the spindle between the journals b Z1', is secured to the sleeve by means of screws Z,inserted through slots m in the spindle, as shown in the section in Fig. 6. rlhe plug is formed, as usual, with a shank, E', extending within the bore of the spindle, and in the construction shown in the shell K the sleeve F may be inade disconnected from the shank l and operated by mere contact therewith, as at its rear end,E-'.

Io produce the forward movement of the collar G2, the head H and cone Jil are therefore shown in Fig. 5 located in the rear of the collar, the sloping face of the latter being inclined at G, s0 that as the ends of the levers I2 are pressed toward the spindle in contact with such face the resultant movement ofthe collar and sleeve F' is toward the nose of the spindle and operates to press the plug toward its seat in the shell K. The ends of the lever which operate with the cone are shown considerably longer than the opposite ends, which thrust against the collar G2, t0

secure an increased leverage and augmented pressure of the plug E upon its seat; and as the levers thrust with their ends against the collar the inclination of its face G (which is nearly at right angles to the shorter ends of the levers,) operates to lock the chuck-plug when pressed upon its seat, and prevents any reactionary movement of the sleeve F on the levers I2. In this respect my invention differs from that of any other lever which has been used in a construction for shifting the chuck-plug, as the reaction of the plug has heretofore operated to press such levers sidewise, so that the holding of the plug firmly upon its seat depended upon some additional locking device-as the cylindrical seat J. (Shown at the base of the cone J in Fig. l.) NVhile such cylindrical seat serves to lock a pair of clutch-levers in a given position, the force exerted tends to bend such levers sidewise, and is all transmitted through the fulcrum-pins of such levers, which are liable to wear loose and derange the operation of the mechanism. In the construction shown in Fig. 5 the shorter ends of the levers become jammed by their radial bearing against the sloping face G when the plug is pressed firmly upon its seat, and the plug is thus held firmly without reference to the stiffness or lateral strength of the levers. The inclination of the face G may be varied to give the plug the desired movement, and a curve eccentric to the fulcruni-pins I may be formed upon the face of the collar, as shown in Fig. 5, with a concentric portion at the base of such curve, to lock the collar into its final position against the ends of the levers. Such eccentric curve is indicated by the dotted line e in Fig. 5, a curve concentric with the fulcrum I being also indicated at e', to show the difference between the two, and an arrow being carried from the curve e to its center to show the location of the latter. \Vith theconstruction `described in Figs. 1 to 4 the cone J and lever I operate to pull the sleeve backward, and the conical plug E is made largest at its outer end, as shown in Figs. 1, 7, and S, and the plug is fitted directly to the nose of the spindle. )Iy improvement in the chuck-plug bushing is shown in Figs. l and 7. As the plug is of hardened steel and slittcd, as at t in Fig. 7, to permit of its compression, the chips from the rods S are liable to gain access to the tapering seat inthe nose of the spindle and to be pressed or stuck therein by the movement of such hardened plug. As it is difficult to harden the nose ot' the spindle to prevent such adhesion of the chips, I have devised a seat made as a bushing separate from the nose of the spindle and fitted to a slightlytapering socket therein, so as to be driven tightly into the same and there held by friction. Such separate seat or bushing may be readily hardened, and after its insertion in the spindle be accurately ground to forni a true tapering seat,and,being of equal hardness with the split plug E, the chips turned from the rods S are not liable to injure the surface of either the plug or seat.

I am fully aware that it is not new to shift the chuck-plug by a sleeve passing through a hollow spindle, and that bent levers having theirl ends inserted through slots in the spindle and acting upon sockets formed in the rear end of the sleeve have been used in conjunction with a shifting-cone to aetuate the sleeve and chuck-plug. I therefore disclaim such construction because the strain is transmitted through a greater number of joints than in my own, in which the ends of the levers jam against the face of the collar G in such a manner as to be self-locking when the chuck is closed, and operate to hold the chuck-plug firmly upon its scat without producing any transverse or bending strain in the arms of the levers.

In my invention both arms of the levers lie outside of the spindle and extend longitudr nally along the same, and the thrust-collar requires therefore to project beyond the ,periphery of the spindle; and I have therefore claimed my invention as of such specific construction.

To compensate for the wear of the chuckplug e in its seat, or to compress the plug more TOO IIO

closely to fit a smaller rod, the head H may have alongitudinal adjustment upon the spindle, as is indicated in a nut, r, shown in Figs. 2 and 5, which is iitted to a screw-thread, s, upon the spindle upon the side of the head opposite the collar G or G2.

The nut I construct with aparting at one side, and insert a clamping-screw, t, to pinch it rmly upon the thread s when adjusted in its proper position.

Having thus disclaimed the use of the levers I and the cone J, unless combined with the thrust-collar G, operating as described herein, I claim my specific construction as follows:

1. The combination, with the hollow spindle, the conical chuck-plug, and the sleeve for actuating the plug, of thecollar rigidly secured to the sleeve and projecting beyond the periphery of the spindle, the cone fitted to slide upon the hollow spindle adjacent to the collar, and one or more levers pivoted to a Afulcruin upon the spindle and extended longif tudinally between the collar and the cone,with one end against `the collar outsidev of the spindle and operating to thrust the collar longitudinally when such end is pressed toward the spindle by the outward movement of its opposite end in contact with the cone, substantially as and forthe purpose set forth.

2. The combination, with the hollow spindle, the conical chuck-plug, and the sleeve for actuating the plug, of the collar rigidly secured to the sleeve beyond the end of the spindle, the cone fitted to slide upon the hollow spindle adjacent to the collar, a longitudinallyadjustable head secured upon the spindle between the collar and thelsone, and a pair of levers pivoted opposite to one another in such head with one end against the collar and operating to thrust the collar and the sleeve longitudinally when such ends are pressed toward the spindle by the expansion of their opposite ends in contact with the cone, substantially as shown and described.

3. The combination, with a hollow spindle, its contained sleeve, and the collar secured thereto and projected beyond the periphery of the spindle, of a pair of levers pivoted upon a head and attached to the spindle, as described, and a cone for separating the levers at one end thereof, the aforesaid collar having a beveled or sloping face in contact with the opposite ends of the levers, operating, when such ends are pressed toward the spindle, to produce a longitudinal movement of the sleeve, substantially as and for the purpose set forth.

4. The combination, with a hollow spindle having a recess formed in its nose, of a hardcned-steel bushing secured within such recess and ground with a conical seat tapering in: wardly, a split conical plug fitted to such seat, and a sleeve attached to the inner end of the plug and movable longitudinally to draw the plug into the seat to operate as a chuck, substantially as shown and described.

. In testimony whereof I have hereunto set.

my hand in the presence of two subscribing witnesses.

ALBERT E. ELMER.

Witnesses:

ALLEN WEBsTER, FRED L. R. BROWN. 

